| 摘要 |
856,232. Cartridge-actuated fastener-driving tools. TERMET, P. Nov. 24, 1958 [Nov. 29, 1957], No. 37704/58. Class 119. Relates to a fastener-driving tool of the kind in which the explosion gases move a piston unit which drives the fastener into the workpiece. According to the invention the piston unit 5 Fig. 1 moves in a cylinder 4 held by threading 6 in a sleeve 7 screwed to a separate breech part 1 incorporating the cartridge chamber 3 which is normally closed at its forward end by a rod 47 integral with the piston 5 and passing through a bore in the otherwise closed rear end of the cylinder 4. The closed end of the cylinder 4 has a tapered surface 52 so as to form with a correspondingly tapered recess in the forward portion of the breech part 1, an annular orifice and space which can be varied in width by adjustment of the cylinder 4 in the threading 6 of the sleeve 7. The arrangement is such that on firing, the initial movement of the piston 5 and rod 47 uncovers the annular orifice and permits part of the explosion gases to pass through the annular space, between the cylinder 4 and sleeve 7 and through baffles 53 to atmosphere. The fire-power of a standard cartridge can thus be varied by adjustment of the width of the annular orifice. In a modification, the rod 47 is provided with a projection 48 in Fig. 4 which projects more or less into the cartridge chamber according to the adjustment of the cylinder 4 and provides a further adjustment of the fire-power by variation of the size of the cartridge chamber. A tube 14 Fig. 1 acts as a guide for the fastener 59 and is extended inwardly by a cage 15 containing magnets 17 for holding the fastener in place. The tube 14 comprises also hollow screws 18 containing magnets 19 for holding to the muzzle an attachment member 60 Fig. 6 (not shown) which is to be fixed to the workpiece by the fastener. The breech part 1 is provided with a pair of holes 41 in which are mounted spring-urged cartridge ejector pins 42. A tubular rubber element 56 is used as a brake for the piston unit and is driven forward to engage a washer 57, e.g. of polyvinylchloride. |
